I use "Q" to make my selection with the selection brush. I like this mode, because I can see better what's in and out of my selection.
If I click on "Refine selection" without quitting the quick mask mode with "q", all my input is not accepted.
I can use the brush to paint and I see a short progress monitor, but it does not work.
Only if I quit the quick mask before clicking "refine selection" it works as expected.